This invention relates to chromatography and more particularly to microscale chromatography.
Microscale chromatography includes the same apparatus on a very much smaller scale as high performance liquid chromatography. A common column diameter for micro liquid chromatography is one millimeter and a common conventional high performance liquid chromatography column diameter is 4.6 millimeters.
In the known microscale chromatographs, flow cells having a lower volume than conventional high pressure liquid chromatographs are used to monitor the eluate. These flow cells have viewing windows for transmitting light through a light path and have inlet and outlet paths.
In the prior art microliquid chromatographs, the flow paths through the flow cells have had large volumes and in one embodiment, the light path is a transmission path through a continuous straight diameter flow path between the inlet and outlet.
The prior art flow cells have several disadvantages such as: (1) they are difficult to fabricate; (2) they have had large volume resulting in bandspreading; and (3) they have not had desirable reflectivity and smoothness of the walls of the light path.